#!/usr/bin/python
# Copyright 2013 Google Inc.
#
# This file is part of Ansible
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

DOCUMENTATION = '''
---
module: gce_pd
short_description: utilize GCE persistent disk resources
description:
    - This module can create and destroy unformatted GCE persistent disks
      U(https://developers.google.com/compute/docs/disks#persistentdisks).
      It also supports attaching and detaching disks from running instances
      but does not support creating boot disks from images or snapshots.  The
      'gce' module supports creating instances with boot disks.
      Full install/configuration instructions for the gce* modules can
      be found in the comments of ansible/test/gce_tests.py.
options:
  detach_only:
    description:
      - do not destroy the disk, merely detach it from an instance
    required: false
    default: "no"
    choices: ["yes", "no"]
    aliases: []
  instance_name:
    description:
      - instance name if you wish to attach or detach the disk 
    required: false
    default: null 
    aliases: []
  mode:
    description:
      - GCE mount mode of disk, READ_ONLY (default) or READ_WRITE
    required: false
    default: "READ_ONLY" 
    choices: ["READ_WRITE", "READ_ONLY"]
    aliases: []
  name:
    description:
      - name of the disk
    required: true
    default: null 
    aliases: []
  size_gb:
    description:
      - whole integer size of disk (in GB) to create, default is 10 GB
    required: false
    default: 10
    aliases: []
  state:
    description:
      - desired state of the persistent disk
    required: false
    default: "present"
    choices: ["active", "present", "absent", "deleted"]
    aliases: []
  zone:
    description:
      - zone in which to create the disk
    required: false
    default: "us-central1-b"
    aliases: []

requirements: [ "libcloud" ]
author: Eric Johnson <erjohnso@google.com>
'''

EXAMPLES = '''
# Simple attachment action to an existing instance
- local_action: 
    module: gce_pd 
    instance_name: notlocalhost
    size_gb: 5 
    name: pd
'''

import sys

USER_AGENT_PRODUCT="Ansible-gce_pd"
USER_AGENT_VERSION="v1beta15"

try:                                                                            
    from libcloud.compute.types import Provider                                 
    from libcloud.compute.providers import get_driver                           
    from libcloud.common.google import GoogleBaseError, QuotaExceededError, \
            ResourceExistsError, ResourceNotFoundError, ResourceInUseError
    _ = Provider.GCE                                                            
except ImportError:                                                             
    print("failed=True " + \
        "msg='libcloud with GCE support is required for this module.'")
    sys.exit(1)                                                                 
                                                                                
# Load in the libcloud secrets file                                             
try:                                                                            
    import secrets                                                              
except ImportError:                                                             
    secrets = None                                                              
ARGS = getattr(secrets, 'GCE_PARAMS', ())                                       
KWARGS = getattr(secrets, 'GCE_KEYWORD_PARAMS', {})                             

if not ARGS or not 'project' in KWARGS:
    print("failed=True " + \
        "msg='Missing GCE connection parameters in libcloud secrets file.'")
    sys.exit(1)

def unexpected_error_msg(error):
    msg='Unexpected response: HTTP return_code['
    msg+='%s], API error code[%s] and message: %s' % (
        error.http_code, error.code, str(error.value))
    return msg

def main():
    module = AnsibleModule(
        argument_spec = dict(
            detach_only = dict(choice=BOOLEANS),
            instance_name = dict(),
            mode = dict(default='READ_ONLY',
                choices=['READ_WRITE', 'READ_ONLY']),
            name = dict(required=True),
            size_gb = dict(default=10),
            state = dict(default='present'),
            zone = dict(default='us-central1-b'),
        )
    )

    detach_only = module.params.get('detach_only')
    instance_name = module.params.get('instance_name')
    mode = module.params.get('mode')
    name = module.params.get('name')
    size_gb = module.params.get('size_gb')
    state = module.params.get('state')
    zone = module.params.get('zone')

    if detach_only and not instance_name:
        module.fail_json(
            msg='Must specify an instance name when detaching a disk',
            changed=False)

    try:
        gce = get_driver(Provider.GCE)(*ARGS, datacenter=zone, **KWARGS)
        gce.connection.user_agent_append("%s/%s" % (
                USER_AGENT_PRODUCT, USER_AGENT_VERSION))
    except Exception as e:
        module.fail_json(msg=unexpected_error_msg(e), changed=False)

    disk = inst = None
    changed = is_attached = False

    json_output = { 'name': name, 'zone': zone, 'state': state }
    if detach_only:
        json_output['detach_only'] = True
        json_output['detached_from_instance'] = instance_name

    if instance_name:
        # user wants to attach/detach from an existing instance
        try:
            inst = gce.ex_get_node(instance_name, zone)
            # is the disk attached?
            for d in inst.extra['disks']:
                if d['deviceName'] == name:
                    is_attached = True
                    json_output['attached_mode'] = d['mode']
                    json_output['attached_to_instance'] = inst.name
        except:
            pass

    # find disk if it already exists
    try:
        disk = gce.ex_get_volume(name)
        json_output['size_gb'] = int(disk.size)
    except ResourceNotFoundError:
        pass
    except Exception as e:
        module.fail_json(msg=unexpected_error_msg(e), changed=False)

    # user wants a disk to exist.  If "instance_name" is supplied the user
    # also wants it attached
    if state in ['active', 'present']:

        if not size_gb:
            module.fail_json(msg="Must supply a size_gb", changed=False)
        try:
            size_gb = int(round(float(size_gb)))
            if size_gb < 1: 
                raise Exception
        except:        
            module.fail_json(msg="Must supply a size_gb larger than 1 GB",
                    changed=False)

        if instance_name and inst is None:
            module.fail_json(msg='Instance %s does not exist in zone %s' % (
                    instance_name, zone), changed=False)

        if not disk:
            try:
                disk = gce.create_volume(size_gb, name, location=zone)
            except ResourceExistsError:
                pass
            except QuotaExceededError:
                module.fail_json(msg='Requested disk size exceeds quota',
                        changed=False)
            except Exception as e:
                module.fail_json(msg=unexpected_error_msg(e), changed=False)
            json_output['size_gb'] = size_gb
            changed = True
        if inst and not is_attached:
            try:
                gce.attach_volume(inst, disk, device=name, ex_mode=mode)
            except Exception as e:
                module.fail_json(msg=unexpected_error_msg(e), changed=False)
            json_output['attached_to_instance'] = inst.name
            json_output['attached_mode'] = mode
            changed = True

    # user wants to delete a disk (or perhaps just detach it).
    if state in ['absent', 'deleted'] and disk:

        if inst and is_attached:
            try:
                gce.detach_volume(disk, ex_node=inst)
            except Exception as e:
                module.fail_json(msg=unexpected_error_msg(e), changed=False)
            changed = True
        if not detach_only:
            try:
                gce.destroy_volume(disk)
            except ResourceInUseError as e:
                module.fail_json(msg=str(e.value), changed=False)
            except Exception as e:
                module.fail_json(msg=unexpected_error_msg(e), changed=False)
            changed = True

    json_output['changed'] = changed
    print json.dumps(json_output)
    sys.exit(0)

# this is magic, see lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>

main()
